Comparative Transcriptomic Analysis of Biological Process and Key Pathway in Three Cotton (Gossypium spp.) Species Under Drought Stress.

Drought is one of the most important abiotic stresses that seriously affects cotton growth, development, and production worldwide. However, the molecular mechanism, key pathway, and responsible genes for drought tolerance incotton have not been stated clearly. In this research, high-throughput next generation sequencing technique was utilized to investigate gene expression profiles of three cotton species (Gossypium hirsutum, Gossypium arboreum, and Gossypium barbadense L.) under drought stress. A total of 6968 differentially expressed genes (DEGs) were identified, where 2053, 742, and 4173 genes were tested as statistically significant; 648, 320, and 1998 genes were up-regulated, and 1405, 422, and 2175 were down-regulated in TM-1, Zhongmian-16, and Pima4-S, respectively. Total DEGs were annotated and classified into functional groups under gene ontology analysis. The biological process was present only in tolerant species(TM-1), indicating drought tolerance condition. The Kyoto encyclopedia of genes and genomes showed the involvement of plant hormone signal transduction and metabolic pathways enrichment under drought stress. Several transcription factors associated with ethylene-responsive genes (ICE1, MYB44, FAMA, etc.) were identified as playing key roles in acclimatizing to drought stress. Drought also caused significant changes in the expression of certain functional genes linked to abscisic acid (ABA) responses (NCED, PYL, PP2C, and SRK2E), reactive oxygen species (ROS) related in small heat shock protein and 18.1 kDa I heat shock protein, YLS3, and ODORANT1 genes. These results will provide deeper insights into the molecular mechanisms of drought stress adaptation in cotton.

Kernel elongation in rice.

Kernel elongation after cooking is an important character of fine rice and most rice consumers prefer length-wise elongation. Although improvement of aromatic rice began early in the 1970s, until now the mechanisms and genetics of kernel elongation has remained unrevealed. Kernel elongation is considered as a physical phenomenon and is influenced by several physicochemical and genetic factors, including genotypes, aging temperature, aging time, water uptake, amylose content and gelatinization temperature. Recently the complete genetic map of fine rice has been created and the gene responsible for kernel length identified; moreover, this gene is tightly linked with the cooked kernel elongation trait. Several molecular markers linked with cooked kernel elongation have been developed. These tools will be helpful for the improvement of this important trait. For the proper study of cooked kernel elongation of rice, this review paper will provide the basis and directional materials for further studies.

Typification and Nomenclature Notes on Twenty-Nine Names in Asparagus (Asparagaceae).

Nomenclatural types for twenty-nine names belonging to the genus Asparagus are typified and discussed. The following names are lectotypified: A. altiscandens Engl. & Gilg, A. altissimus Munby, A. baumii Engl. & Gilg, A. benguellensis Baker, A. burchellii Baker, A. curillus Buch.-Ham. ex Roxb., A. deflexus Baker, A. duchesnei L.Linden, A. equisetoides Welw. ex Baker, A. fasciculatus Thunb., A. griffithii, Baker, A. homblei De Wild., A. kaessneri De Wild., A. lecardii De Wild., A. longicladus N.E.Br., A. longiflorus Franch., A. monophyllus Baker, A. palaestinus Baker, A. pastorianus Webb & Berthel., A. persicus Baker, A. poissonii H.Perrier, A. psilurus Welw. ex Baker, A. ritschardii De Wild., A. sapinii De Wild., A. scandens Thunb., A. schumanianus Schltr. ex H.Perrier, A. stellatus Baker, A. subfalcatus De Wild., and A. undulatus (L.f.) Thunb. (synonym of Dracaena undulata L.f.). A new name, Asparagus neofasciculatus, is proposed as a replacement name for A. fasciculatus Thunb., which is an illegitimate later homonym of A. fasciculatus R.Br. The original protologue of these names and the original materials are evaluated. Nomenclature remarks discussing the selection of type specimens are given for each name, and known isotypes or isolectotypes are also cited. This information could be utilized as a reference for future taxonomic and systematic studies on Asparagus around the world.

Impact of OsBadh2 Mutations on Salt Stress Response in Rice.

Mutations in the Betaine aldehyde dehydrogenase 2 (OsBadh2) gene resulted in aroma, which is a highly preferred grain quality attribute in rice. However, research on naturally occurring aromatic rice has revealed ambiguity and controversy regarding aroma emission, stress tolerance, and response to salinity. In this study, mutant lines of two non-aromatic varieties, Huaidao#5 (WT_HD) and Jiahua#1 (WT_JH), were generated by targeted mutagenesis of OsBadh2 using CRISPR/Cas9 technology. The mutant lines of both varieties became aromatic; however, WT_HD mutants exhibited an improved tolerance, while those of WT_JH showed a reduced tolerance to salt stress. To gain insight into the molecular mechanism leading to the opposite effects, comparative analyses of the physiological activities and expressions of aroma- and salinity-related genes were investigated. The WT_HD mutants had a lower mean increment rate of malondialdehyde, superoxide dismutase, glutamate, and proline content, with a higher mean increment rate of γ-aminobutyric acid, hydrogen peroxide, and catalase than the WT_JH mutants. Fluctuations were also detected in the salinity-related gene expression. Thus, the response mechanism of OsBadh2 mutants is complicated where the genetic makeup of the rice variety and interactions of several genes are involved, which requires more in-depth research to explore the possibility of producing highly tolerant aromatic rice genotypes.

Antimicrobial peptides from different plant sources: Isolation, characterisation, and purification.

Antimicrobial peptides (AMPs), the self-defence products of organisms, are extensively distributed in plants. They can be classified into several groups, including thionins, defensins, snakins, lipid transfer proteins, glycine-rich proteins, cyclotides and hevein-type proteins. AMPs can be extracted and isolated from different plants and plant organs such as stems, roots, seeds, flowers and leaves. They perform various physiological defensive mechanisms to eliminate viruses, bacteria, fungi and parasites, and so could be used as therapeutic and preservative agents. Research on AMPs has sought to obtain more detailed and reliable information regarding the selection of suitable plant sources and the use of appropriate isolation and purification techniques, as well as examining the mode of action of these peptides. Well-established AMP purification techniques currently used include salt precipitation methods, absorption-desorption, a combination of ion-exchange and reversed-phase C18 solid phase extraction, reversed-phase high-performance liquid chromatography (RP-HPLC), and the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method. Beyond these traditional methods, this review aims to highlight new and different approaches to the selection, characterisation, isolation, purification, mode of action and bioactivity assessment of a range of AMPs collected from plant sources. The information gathered will be helpful in the search for novel AMPs distributed in the plant kingdom, as well as providing future directions for the further investigation of AMPs for possible use on humans.